title: Evidence of impaired brain activity balance after passive sensorimotor stimulation in multiple sclerosis.
abstract: OBJECTIVE
  Examination of sensorimotor activation alone in multiple sclerosis (MS) patients may not yield a comprehensive view of cerebral response to task stimulation. Additional information may be obtained by examining the negative BOLD response (deactivation). Aim of this work was to characterize activation and deactivation patterns during passive hand movements in MS patients.
  
  
  METHODS
  13 relapsing remitting-MS patients (RRMS), 18 secondary progressive-MS patients (SPMS) and 15 healthy controls (HC) underwent an fMRI study during passive right-hand movements. Activation and deactivation contrasts in the three groups were entered into ANOVA, age and gender corrected. Post-hoc analysis was performed with one-sample and two-sample t-tests. For each patient we obtained lesion volume (LV) from both T1- and T2-weighted images.
  
  
  RESULTS
  Activations showed a progressive extension to the ipsilateral brain hemisphere according to the group and the clinical form (HC<RRMS<SPMS). Significant deactivation of the ipsilateral cortical sensorimotor areas was reduced in both patient groups with respect to HC. Deactivation of posterior cortical areas belonging to the default mode network (DMN), was increased in RRMS, but not in SPMS, with respect to HC. The amount of activation in the contralateral sensorimotor cortex was significantly correlated with that of deactivation in the DMN in HC and RRMS, but not in SPMS. Both increased activation and decreased deactivation patterns correlated with LV.
  
  
  CONCLUSIONS
  In RRMS patients, increased cortical activation was associated with increased deactivation of the posterior cortex suggesting a greater resting-state activity in the DMN, probably aimed at facilitating sensorimotor circuit engagement during task performance. In SPMS the coupling between increased sensorimotor activation/increased DMN deactivation was not observed suggesting disorganization between anticorrelated functional networks as a consequence of a higher level of disconnection.
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy. petsas@gmail.com
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Petsas
authors.forename: Emanuele
authors.initials: E
authors.lastname: Tinelli
authors.forename: Delia
authors.initials: D
authors.lastname: Lenzi
authors.forename: Valentina
authors.initials: V
authors.lastname: Tomassini
authors.forename: Emilia
authors.initials: E
authors.lastname: Sbardella
authors.forename: Francesca
authors.initials: F
authors.lastname: Tona
authors.forename: Eytan
authors.initials: E
authors.lastname: Raz
authors.forename: Valter
authors.initials: V
authors.lastname: Nucciarelli
authors.forename: Carlo
authors.initials: C
authors.lastname: Pozzilli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pantano
mesh_terms: D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D056228:Feedback, Sensory; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement; D020528:Multiple Sclerosis, Chronic Progressive / Q000503:physiopathology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology*; D010812:Physical Stimulation; D013003:Somatosensory Cortex / Q000503:physiopathology*